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UNITED STATES ess Reference PATENT OFFICE,

SAMUEL It. PERCY AND HENRY A. MOTT, JR, OF NEW YORK, X. Y., ASSlGKOItS ()F TYVO-THIRDS TO SAID PERCY AND ONE-THIRD TO SAID MOTT.

MANUFACTURE OF PAINTS FOR SHIPS BOTTOMS, 84.0.

SPECIFICATION forming part of Letters Patent No. 251,279, dated December 20, 1881.

Application filed January 28, 1881. (X0 specimens.)

To all whom it may concern.-

Be it known that we, SAMUEL R. PERCY and HENRY A. MOTT, Jr., both of the city of New York, in the county of New York and State of New York, have invented an Improvement in the Manufacture of Paints for Ships Bottoms, &c., of which the following is a specification.

Our invention relates to the manufacture of a paint adapted for the preservation of wood and all timbers situated or submerged under water, having particularreterence to thepainting of the bottoms of vessels, Both iron and wood, timber used in the construction of docks, piles, &c.; and itconsists in incorporating with any metallic or other paint, picric acid, basic picrate of lead, or any compound of picric acid, or using picric acid alone for the primary coat and an insoluble paint as the secondary coat, as more fully hereinafter set forth.

The object of our invention is to produce a new composition or paint for coating the surface of timber, 810., for the prevention of the growth of grass, barnat-les, &c., and insects of any kind from boring into the wood and thereby destroying the same.

The essential feature of this invention consists in the application, mixing, or incorporation of axbitter and poisonous substance into the paint as more commonly manufactured, or any other compound used for painting or coating the surface of submerged timbers. The ingredient most adapted to this invention is the basic picratc of lead, (triplumbic picrate,) for the reason that it is a compound of lead, and well adapted to be mixed with any solvent for metallic or other paint or mixed with such paint. In place of basic picrate of lead, picric acid, alkaline or earthy picrates, or picrates in any combination which renders them insoluble in water may he used, for in all of these compounds picric acid is to be found.

PlCllC acid-sometimes known as carba- .zotic, trinitrophuric, or nitrophenisic G.4Pb0) is, however, the most desirable. of all the compounds of picric acid, and may be prepared as follows: A solution of dilute neutral acetate of lead is precipitated with picrate of ammonia (a commercial compound) containing an excess of ammonia. The precipitate, which is the basic picrate of lead, is of a deep-yellow powder. Any other process to produce pier-ate of lead, whether the tri or other basic salt or any of the combinations of picric acid hereinbet'ore enumerated, may be used, if desired.

The basic pier-ate of lead may be used as the basis of a paint without admixture with other paints; but as this salt is somewhat expensive, we mix with it, or one of its combinations, some copper or lead paint, or any of the earthy or silicious paints.

In place of using a compound picrate-of-lead paint, as described above, a watery solution of picric acid may be applied, and afterward a lead or other salt to decompose and render insoluble the picric acid, either upon the surface or within the wood.

If desired, a solution of picric acid may be applied to the wood, and when dry a coating of composition paintmay be applied. Asmany coats may be applied as desired or as circumstances require.

The value of this composition is that it is destructive to all forms of life, whether vegetable or animal, and so bitter that insects will not bore into or live upon it.

In this application the invention relates exclusively to the use of picric acid or picrates as a paint, in which it is either mixed with some well-known andcommon insoluble paint or is applied first on the surface and afterward covered with aeoating 0t insoluble paint, in distinction to impregnating timber with a solution of resinous substance and picric acid, which is forced into the pores of the wood,impregnating the same, as this latter forms subject-matter of another application in the name of Samuel R. Percy.

In British Provisional Protection No. 301 of 1871 is described a grease composition to protect the bottoms of iron ships from rusting, in which picric acid orcreosote may be used; but

7 Search Rose such composition bears no relation to a paint, in the true sense of the term, as it is designed to be smeared over the bottom of the ship,and

'any such layer could not last any great length of time, as the picric acid would soon dissolve out and the grease or tallow be rubbed ofi' if the bottom of the vessel should pass over any brush or any floating substance. That grease com position is adapted toiron surtaces, whereas our insoluble paint is especially adapted to wooden surfaces.

Having now described our invention, what we claim as new, and desire to secure by Letters Patent, is

-1. As a new article of manufacture, an insoluble paint consisting of the admixture with any insoluble paint, as a lead or copper paint, of 'picric acid or picrate, said compound paint having a solvent; capable of evaporating to 20 leave the paint as a hard insoluble coating all?" SAML. R. PERCY. HENRY A. MOTT, JR.

Witnesses:

GILBERT S. VAN PELT, AUSTIN S. UUSHMAN. 

